hulbert



(No Model.)

O. L. HULBERT. PROGESS 0F BURNISHING 'UNMOUNTBD MULTIPLE PHOTOGRAP-HIOSHEETS.

Patented'June 29, 1886 A es UNITED STATES PATENT OFFICE.

OBRIN L. HULBERT, OF ST. LOUIS, MISSOURI, ASSIGNOR TO HULBERT BROTHERS,OF SAME PLACE.

, PROCESS OF BURNlSHlNG UNMOUNTED MULTIPLE PHOTOGRAPHIC SHEETS.

SPECIFICATION f imin part of Letters Patent NO. 344,781, dated June 29,1886.

Serial No. 186,735. (No model.)

To ctZZ whom it may concern;

Be it known that I, ORRIN L. HULBERT, of the city of St. Louis, inthe-State of Missouri, have invented a certain new and useful Process ofBurnishing Unmounted Multiple Photographic Sheets, of which thefollowing is a full. clear, and exact description, reference being hadto the accompanying drawings, forming part of this specification, and inwhich- Figure l is a perspective view of the apparatus, and Fig. 2 is avertical transverse section.

It has been the practice for some time to calender the sheets of paper,and it has also been a somewhat common practice to burnish unmountedsheets of photographs; but my process of burnishing unmounted multiplesheets of photographs differs materially from the old modes ofburnishing unmounted sheets and oalendering paper, and these unmountedmultiple ph otographsheets present special difficultiesin burnishing andfinishing by reason of their essential peculiarities. For example, theyare not made around a single focus like a single picture with numerousfoci, and on such a small scale that great sharpness is necessary toproduce a satisfactory effect. It is the purpose of myimproved mode ofburnishing to develop, bring out, and heighten this effect, which ispeculiarly important in this product, because of not dealing with singlepictures such as have heretofore been supplied to the trade on unmountedsheets, but with numerous pictures each having its own independenteffect while they are all united on one sheet, and hence it is thatmeans heretofore employed for calendering paper or burnishing unmountedphotographs are not available or satisfactory for the finish of thesemultiplephotograph-sheets. Another reason why the old processes wouldnot be available or satisfactory for these multiple photograph-sheets isthat the pictures on asheet are either detached from each other orseparated by intervening rows of perforations after burnishing, and inperforming either of the operations the burnish or a portion of it isdestroyed unless a much heavier pressure is brought to bear ona printwhile burnishing than can be brought upon a thin sheet by the ordinaryprocesses of burnishing and calendering, and by the ordi nary processesused a sufficient pressure can not be made and a sufficiently fineburnish cannot be produced to prevent the destroying of the burnish, asabove stated, a very high U pressure being necessary where the sheet hasto be perforated to compact the paper and make it solid. Anotherdifficulty in burnishing these multiple photograplrsheets by any oldprocess is that when an attempt is made to produce a fine burnish thecenter will have a finer burnish than the edges. This would answer thepurpose on a single photograph, because the center is preferred to besharper than the outside; but with a number of photographs on a sheet itwould not besatisfactory, as the center ones would have a finer burnishthan the others,and a customer would object to a sheet of photographsdiffering in appearance, as they would if they were not all burnishedalike.

By a series of experiments I have succeeded in burnishing theseunmounted multiple ph0- tograph-sheets by a method which I believe to beentirely new, and one, in the present state of the art ofphotography,which appears to me to be essential to produce thesepictures with a sufficiently fine burnish to satisfy the trade. Myimproved method is as follows: I first take a three-ply bristol-board,A, and fold the edge of the photograph-sheet B over one end of thebristolboard, as shown at C in the drawings, and then pass the twothrough the burnisher three or four times, preferring to wrap themaround the roller F,'as shown, as they pass throughin the directionindicated by the arrows, Fig. 2. The face of the photograph bears upon asteel plate, D, which is heated from below by means of a suitableburner, E. This plate Dis made of malleable silver steel, tempered andpolished, and is particularly suited for this purpose, the ordinarymetal or cast-steel ordinarily used in burnishing having failed toproduce the desired result, not having a sufficiently fine and solidsurface, but being too coarse or having too much grain in itscomposition. The plates as ordinarily used in burnishing are suitablefor burnishing mounted photographs, because the mount prevents anyslipping or rumpling of the picture when considerable friction orpressure is applied; but when the necessary amount of friction orpressure is applied to the unmounted sheet with the old form of plate,it would be creased and rumpled and frequently destroyed and torn, owingto the grain of the metal being coarse, taking too great a hold of it;but with the kind of metal I use for this purpose these difiiculties areavoided. Before passing the sheets through the burnisher I lubricate theface of the photograph-sheet with a solution of white wax dissolved insulphuric ether, to which is added a suificient quantity of alcohol forthe purpose of thinning it. I am enabled by this process to producejustas fine a burnish upon an unmounted photograph-sheet and upon eachsingle photograph (if not finer) than has been produced upon mountedphotographs, and I am enabled to burnish thousands of these unmountedmultiple photograph-sheetswithout destroying or injuring one, giving toeach-an unexcelled appearance.

The three distinguishing features of-my'improved method and apparatusare, first,-wrapping the edge of the photograph-sheet around the edge orend of the bristol-board before passing them through theburnishertogether; second, making the plate of the burnisher ofmalleable silver steel; and, third, lubricating the photographs withwhite wax and ether.

As an equivalent of wrapping the edge of the photograph over the edge ofthe bristolboard, they may be stuck together at the edge by glue,mucilage, or other adhesive.

I claim as my invention 1. The improved method of burnishing unmountedmultiple photograph sheets by first lubricating them, then placing themon a back eating them with a mixture of white wax and ether, thenplacing them on a backing of bristol-board,around which one edge iswrapped, then passing them through a burnisher having a plate made ofmalleable silver steel heated from below, substantially as described.

ORRIN L. HULBERT. In presence of 'EDW. S. KNIGHT, J OE. WAHLE.

